The application relates to a portable electronic device comprising a wireless receiver unit for receiving a wireless signal from a transmitting device, the wireless receiver unit comprising an antenna for receiving an electromagnetic signal and providing a received electric input signal, and a receiver for providing a recovered electric signal from the received electric input signal, and an impedance matching circuit for matching the electric impedance of the antenna to the receiver, the receiver comprising a gain stage comprising an Automatic Gain Control unit for automatically determining an AGC-gain value for application to an AGC-input signal to provide an appropriate signal level of the recovered electric signal when the level of said AGC input signal is in a range between a minimum signal level and a maximum signal level corresponding to maximum and minimum AGC-gain values, respectively. The application further relates to a method of operating a wireless receiver unit, to the use of a portable electronic device and to a communication system. The object of the present application is to provide a scheme for improving flexibility in the acceptable range of operation of a wireless link. The problem is solved in that the portable electronic device further comprises a control unit receiving said AGC-gain value and providing a control signal depending on said AGC-gain value to said impedance matching circuit, and wherein the control unit is adapted to change the impedance matching of the antenna to the receiver based on the control signal. This has the advantage of enhancing the dynamic range of the wireless receiver, e.g. allowing a smaller minimum distance between transmitter and receiver.